function calc(a,b,callback){
    return callback(a,b)
}

function add(a,b){
    return a+b
}

function plus(a,b){
    return a*b
}

let a=calc(10,20,plus)
// let b=calc(10,20,function(a,b){
//     return a/b
// })
let b=calc(10,20,(a,b)=>a/b)
console.log(a,b);